I did send via recorded delivery all the info they wanted
1/ Was this the licence holder details as required on the CoFP (not original NIP/S172 request? Dates on the tracking receipt will give a clue).
2/ Does the PO tracking indicate they were delivered or not?
IF (and that's a
IF ) You fully complied with the terms of the offer you should/could plead not guilty as they are barred from raising a court case if you did.
I guess ill have to phone citizen advice?
I wouldn't, you'll get much better and more experienced advise on here.
I guess they want to charge me more?
No they think you didn't fully comply with the terms of the offer so couldn't process it.